Technical Field
The present disclosure relates to a touch sensing system and a display device including the same.
Description of the Related Art
Facing information society, display field of displaying electric information signals has been rapidly advanced, and accordingly, various flat display devices have been developed and used. As flat display devices, a liquid crystal display device (LCD), a plasma display panel device (PDP), an organic light emitting diode (OLED) display device and the like are used.
A touch panel as a user input device is applied to a display device and senses a user's touch.
Recently, to realize an UI (user interface)/UX (user experience), the related art touch sensing system capable of a user touch position and a user recognition as well is provided. This system employs an IR (infrared ray) type touch panel to detect of a user touch position, and a mutual capacitive type touch panel for a user recognition (or user ID).
The IR type touch panel senses an infrared ray from an IR generator and detects a user touch position.
The mutual capacitive type touch panel has a driving electrode and a sensing electrode which are formed entirely over the panel and form a single capacitor, and this capacitor is connected to a resistor and an inductor, which are located outside the panel, to form a RLC band cut filter. At a user touch, an impedance of the RLC filter is measured to recognize a user.
Since the related art touch sensing system requires both of the IR type touch panel and the mutual capacitive type touch panel, a thickness and a cost of the system increase, and a thickness and a cost of a display device using the system increase.
Further, the related art touch sensing system uses the RLC band cut filter for a user recognition. However, the RLC band cut filter has a narrow gain range (or dynamic range) for an impedance measurement due to its characteristics, and a touch detection capability is degraded.